Mersawa tree

Mersawa
Anisoptera costata Korth. 1841.
Anisoptera oblonga Dyer, 1874.
Anisoptera cochinchinensis Pierre, 1890.
Anisoptera robusta Pierre, 1890.
Family: Dipterocarpaceae
Order: Malvaceae cotton

Identifying characteristics:
Large evergreen tree , 30 - 40 m high, 50 - 80 cm diameter or more. The bark is grey-brown, smooth when young, deeply cracked when old. Young branches are covered with dense yellow star-shaped hairs. The leaves are simple, whole, oval-shaped, 10 - 17 cm long, 5 - 8 cm wide, the top has a short pointed tip, the base is blunt or slightly heart-shaped, the upper surface is smooth, the lower surface has star-shaped hairs, which soon fall off; Side veins 12 - 17 pairs (small leaves) or 20 - 24 pairs (large leaves). The stipules are small, spear-shaped, and hairy. Inflorescences are inflorescences, 10 - 15 cm long, growing in the leaf axils or at the top of the branches, with star-shaped hairs. The sepals are hairy, the outer sepals are slightly longer than the inner sepals. Petals are blunt spear-shaped, white. Stamens 30 - 35. The ovary is submerged in the flower base, 2 cells, each cell has 2 ovules; The proboscis is long, oblong, hairy, and has 3 small teeth at the top. The fruit is nearly spherical, brown, about 1cm in diameter, with a spout at the top; The 2 large wings are 12 cm long and 2 cm wide, the other 3 wings are only 2.5 cm long.

Biology and ecology.
Flowering season is December - March (next year), fruiting is April - May. The tree grows in closed, moist, evergreen or slightly dry forests. Also found in semi-deciduous forests, adjacent to evergreen forests with the dominant Lagerstroemia. Together they grow Black Star, Dau rai, Sen pus, Sticky rice..., rarely seen Ven ven growing in nearly pure forests.

Distribution:
Domestic: Da Nang, Kontum, Gia Lai, Daklak, Lam Dong, Ninh Thuan, Binh Thuan, Binh Phuoc, Binh Duong, Dong Nai, Ba Ria - Vung Tau, City. Ho Chi Minh, Kien Giang.
World: Myanmar, Thailand, Laos, Cambodia, Malaysia, Philippines, Indonesia.

Value:
The best type of tree for shipbuilding wood in Vietnam. Venetian wood is classified as rosewood, density 0.6 - 0.7; Also used to make furniture, flooring or process plywood and veneer.

Status:
Due to the precious wood, it has been heavily exploited , and the living environment has also been greatly reduced due to serious destruction of primary forests and rich forests. Venetians have been exterminated in a number of provinces and districts in the Southeast region.

Classification : EN A1a,b,c+2b,c.

Protection measures :
Ven ven is protected in Chu Mom Ray National Park , Cat Tien and is grown and cultivated in many provinces in the Southeast region.

Document referenced: Vietnam Red Book 2007 – Plant section – Page 167.